A rectangle-type linear ultrasonic motor using longitudinal vibration transducers with four driving feet

Abstract

To make full use of the vibrational energy of a longitudinal transducer, a rectangle-type linear ultrasonic motor with four driving feet is proposed in this paper. This new motor consists of four longitudinal vibration transducers which are arranged in a rectangle and form an enclosed construction. Lead zirconate titanate ceramics are embedded into the middle of the transducer and fastened by a wedge-caulking mechanism. Each transducer includes an exponentially shaped horn located on each end. The horns of the vertical transducers intersect at the base of the horizontal transducers' horns; the tip ends of the horizontal transducers' horns are used as the driving feet. Longitudinal vibrations are superimposed in the motor and generate elliptical movements at the tip ends of the horns. The working principle of the proposed motor is analyzed. The resonance frequencies of two working modes are tuned to be close to each other by adjusting the structural parameters. Transient analysis is developed to gain the vibration characteristics of the motor. A prototype motor is fabricated and measured. The vibration test results verify the feasibility of the proposed design. Typical output of the prototype is a no-load speed of 928 mm/s and maximum thrust force of 60 N at a voltage of 200 Vrms.

A T-shape linear piezoelectric motor with single foot

“…Furthermore, as two orthogonal vibrations with the same resonance frequency and a temporal phase shift of 90°can also form elliptical movement, combination of vibrations, such as longitudinal and bending vibrations [11][12][13][14], longitudinal and torsional vibrations [15][16][17], two orthogonal longitudinal vibrations [18][19][20][21][22][23][24], and two orthogonal bending vibrations [25][26][27][28][29], can be utilized for constructing piezoelectric motors. Recently, a new principle for linear driving was proposed by Lu et al, in which driving principle using ultrasonic vibration induced friction reduction was proposed and investigated; and the two exciting frequencies of the driving and friction reduction voltages need not to be the same [30].…”

“…Most piezoelectric motors using longitudinal vibrations have bolt-clamped structures as they are usually designed for high output powers under large sizes [18][19][20][21][22][23][24]. However, the proposed motor adopts bonded-type structure for the aim of miniaturization and future application in small system.…”

Research on a Linear Piezoelectric Actuator Using T-Shape Transducer to Realize High Mechanical Output

“…A U-shaped LUSM using longitudinal vibration transducers with double feet has obtained a no-load speed of 854 mm/s and a maximum output thrust of 40 N [16]. There are also some other high-power LUSMs [17][18][19][20]. All these initiative research studies soundly proved that most of the high-power ultrasonic motors adopted the d33 working mode.…”

A three-DOF ultrasonic motor using four piezoelectric ceramic plates in bonded-type structure

“…According to the type of the output motion, ultrasonic motors can be classified into linear type, rotary type and multi-DOF one. The linear actuation of ultrasonic motors can be realized by the hybrid of two independent vibration modes, such as a bending and a longitudinal vibration modes [6][7][8][9][10], two bending vibration modes and two longitudinal modes [11][12][13][14]. The rotary actuation is usually realized by a traveling wave in a ring-type or cylinder-type stator and can also be realized by the hybrid of two vibration modes [15][16][17][18][19].…”